Cma1, also known as Mcpt5 encoding mouse mast cell protease-5, is a gene expressed in mast cells. Chymase, the enzyme it encodes, is involved in tissue remodelling and fibrosis processes. It may also play a role in the renin-angiotensin system, though details are less clear [1,4].

A new inducible mast cell-deficient mouse model (Mcpt5/Cma1DTR) was generated, where the expression of human diphtheria toxin A receptor under the Cma1 promoter enabled almost complete depletion of mast cells upon DT injection. This model is valuable for studying the conditional depletion of all mast cell populations without significantly reducing other cell types, thus helping to understand the in vivo roles of mast cells related to Cma1 [1].

In a study on psoriasis, Cma1 was among nine differential genes identified, affecting amino acid and carnitine metabolism pathways contributing to Th17 cell infiltration in psoriatic lesions [2]. In preeclampsia research, the (TG)n(GA)m repeat downstream of the Cma1 gene was significantly associated with preeclampsia in women, suggesting a possible role of Cma1 polymorphic repeats as susceptibility factors [3].

In conclusion, Cma1 is important in mast cell-related functions and is associated with various disease conditions such as psoriasis and preeclampsia. The Mcpt5/Cma1DTR mouse model provides a valuable research tool for understanding the role of Cma1-expressing mast cells in vivo, contributing to insights in these disease areas.